Observable Collection Property Changed on Item in the Collection

Brute force:

1. Attach handler to each PropertyChanged event for each child item
2. Grab the ListCollectionView from your CollectionViewSource
3. Call Refresh.

EDIT:

The code for 1, 2 would live in your code-behind.

For #1, you'd do something like:

private void Source_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e){    switch (e.Action)    {        case NotifyCollectionChangedAction.Add:            foreach( SomeItem item in e.NewItems)            {               item.PropertyChanged += new PropertyChangedEventHandler(_SomeItem_PropertyChanged);             }            break;....**HANDLE OTHER CASES HERE**....      }}

For #2, in your CollectionChanged handler, you would do something like:

private void _SomeItem_PropertyChanged(object sender, PropertyChangedEventArgs e){    ListCollectionView lcv = (ListCollectionView)(CollectionViewSource.GetDefaultView(theListBox.ItemsSource));    lcv.Refresh();}

EDIT2:However, in this case, I would strongly suggest that you also check ListCollectionView.NeedsRefresh and only refresh if that is set. There's no reason to re-sort if your properties have changed which don't affect the sort.

This works. Whenever the collection changes, it re-sorts the collection. Might be doable in a more efficient way but this is the gist of it.

public partial class TestWindow : Window {        ObservableCollection<TestClass> oc;        public TestWindow() {            InitializeComponent();            // Fill in the OC for testing             oc = new ObservableCollection<TestClass>();            foreach( char c in "abcdefghieeddjko" ) {                oc.Add( new TestClass( c.ToString(), c.ToString(), c.GetHashCode() ) );            }            lstbox.ItemsSource = oc;            // Set up the sorting (this is how you did it.. doesn't work)            lstbox.Items.SortDescriptions.Add( new SortDescription("A", ListSortDirection.Ascending) );            // This is how we're going to do it            oc.CollectionChanged += new System.Collections.Specialized.NotifyCollectionChangedEventHandler( oc_Sort );        }        void oc_Sort( object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e ) {            // This sorts the oc and returns IEnumerable            var items = oc.OrderBy<TestClass, int>( ( x ) => ( x.C ) );            // Rest converst IEnumerable back to OC and assigns it            ObservableCollection<TestClass> temp = new ObservableCollection<TestClass>();            foreach( var item in items ) {                temp.Add( item );            }            oc = temp;        }        private void Button_Click( object sender, RoutedEventArgs e ) {            string a = "grrrr";            string b = "ddddd";            int c = 383857;            oc.Add( new TestClass( a, b, c ) );        }    }    public class TestClass : INotifyPropertyChanged {        private string a;        private string b;        private int c;        public TestClass( string f, string g, int i ) {            a = f;            b = g;            c = i;        }        public string A {            get { return a; }            set { a = value; OnPropertyChanged( "A" ); }        }        public string B {            get { return b; }            set { b = value; OnPropertyChanged( "B" ); }        }        public int C {            get { return c; }            set { c = value; OnPropertyChanged( "C" ); }        }        #region onpropertychanged        public event PropertyChangedEventHandler PropertyChanged;        protected void OnPropertyChanged( string propertyName ) {            if( this.PropertyChanged != null ) {                PropertyChanged( this, new PropertyChangedEventArgs( propertyName ) );            }        }        #endregion    }

XAML:

<Window x:Class="ServiceManager.TestWindow"    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    Title="TestWindow" Height="500" Width="500">    <DockPanel>        <ListBox ItemsSource="{Binding}" x:Name="lstbox">            <ListBox.ItemTemplate>                <DataTemplate>                    <StackPanel Orientation="Horizontal">                        <Label Content="{Binding Path=A}"/>                        <Label Content="{Binding Path=B}"/>                        <Label Content="{Binding Path=C}"/>                    </StackPanel>                </DataTemplate>            </ListBox.ItemTemplate>        </ListBox>        <Button Click="Button_Click" Content="Click" />    </DockPanel></Window>